Apparatus for web feed

Abstract

To join the start of a new web to an expiring web a splicing assembly is provided which includes a light source and photoelectric cell. When a splice is to be effected, the splicer is moved towards the new reel and when the light beam is interrupted by the periphery of the reel the splicer is stopped in the correct position for splicing, and the position of the cell used as an indication of the diameter of the reel; a signal from the cell also causing the reel to be driven at such a speed that the speed of the new reel matches the linear speed of the old web so that the splice may be effected properly.

I claim: 
     
       1. Web feed apparatus comprising a first reel support, a second reel support, and a splicer operable to join a leading end of web from a reel carried by said first support to a running web feeding from a reel carried by said second support, said first support being movable to a datum position after loading of a fresh reel thereon, including a sensing device movable towards the circumferential surface of said reel at said datum position, said sensing device being adapted to respond to proximity of said reel, and means under control of said sensing device for stopping movement of the sensing device so that the sensing device stops in a position dependent upon the reel diameter. 
     
     
       2. Apparatus as claimed in claim 1 in which said sensing device is connected to means for indicating its position, said indicating means being calibrated in terms of reel diameter. 
     
     
       3. Apparatus as claimed in claim 1 in which each of said first and second reel supports includes drive means for rotating a reel supported thereon. 
     
     
       4. Apparatus as claimed in claim 3 in which said sensing device is coupled to said drive means so that the position of the sensing device controls the speed of drive to said fresh reel from the associated drive means. 
     
     
       5. Apparatus as claimed in claim 4 in which said sensing device is mounted on said splicer so that as said sensing device is moved towards the circumferential surface of said fresh reel and stopped, the splicer is brought to a predetermined position relative to said fresh reel. 
     
     
       6. Apparatus as claimed in claim 5 in which said sensing device comprises a photoelectric device arranged so that the passage of a light beam to a photoelectric detector is interrupted by the periphery of said fresh reel.